I'm not too sure whether EVERYONE can live with one lung, but yes, it is defnitely possible. Lungs are balloon like and, for example, if you had a section or part of a lung removed, the lung can sometimes expand to compensate for the removed area and "stretch" itself to a larger size.
You can find an inspiring article here of a man who climbed Mt. Everest with one lung.
You can find an inspiring article here of a man who climbed Mt. Everest with one lung.